Liver tissue-derived ECM loaded nanocellulose-alginate-TCP composite beads for accelerated bone regeneration.

Guided bone regeneration with osteoinductive scaffolds is a competitive edge of tissue engineering due to faster and more consistent healing. In the present study, we developed such composite beads with nanocellulose reinforced alginate hydrogel that carried β -tricalcium phosphate ( β -TCP) nano-powder and liver-derived extracellular matrix (ECM) from porcine. Interestingly, it was observed that the beads' group containing ECM- β- TCP-alginate-nanocellulose (ETAC) was more cytocompatible than the others comprised of β- TCP-alginate-nanocellulose (TAC) and alginate-nanocellulose (AC). Cell attachment on ETAC beads was dramatically increased with time. In parallel with in vitro results, ETAC beads produced uniform cortical and cancellous bone in the femur defect model of rabbits within 2 months. Although the group TAC also produced noticeable bone in the defect site, the healing quality was improved and regeneration was faster after adding ECM. This conclusion was not only confirmed by micro-anatomical analysis but also demonstrated with x-ray microtomography. In addition, the characteristic moldable and injectable properties made ETAC a promising scaffold for clinical applications.